You can do that if you use Usersettings option. If you don’t, you can’t use it because you can’t read user’s sure name like you can read his/her email with USEREMAIL(). If you would like to use the sure name, you should have a convert table (users). You could then read the sure name from that table for the security filter like [SureName]=LOOKUP(USEREMAIL(),Users,Email,SureName). But it’s much more efficient to use just [Email]=USEREMAIL().